A fluorinated carbonyl compound can be prepared from a fluorinated methyl or ethyl ether. In the case of a primary ether, an acylated product results, while in the case of a secondary ether, a ketone results. The reaction of formation involves contacting the fluorinated ether with an appropriate catalyst in a reaction mixture which typically is heated. A solvent may be added to the reaction mixture where desirable.
Numerous catalysts have been proposed for use in such a reaction. Anderson, U.S. Pat. No. 4,357,282, explores the suitability of many catalysts for such purpose, among which is tin tetrachloride (stannic chloride, SnCl.sub.4). It is reported in this reference that when tin tetrachloride is used as a catalyst in this type of a carbonyl-forming reaction, the reaction shows an initial period of activity but then becomes sluggish. This drop in the rate of reaction is attributed to progressive fluorination of the tin tetrachloride.
As tin tetrachloride is a relatively inexpensive material, it would be advantageous to determine a process whereby it could be used efficiently and reliably as a catalyst for the formation of fluorinated carbonyl compounds from a fluorinated methyl or ethyl ether.